| 摘要 |
PURPOSE:To permit no electric writing by preventing the potential of a gate electrode from rising when exposed to a high electric field by connecting the gate electrode with a reverse conductivity type diffused layer to semiconductor substrate provided outside a diffused region. CONSTITUTION:An aluminum electrode 1 (1)-a contact 6 between aluminum/a diffused layer-a diffused layer 7-a contact 8 between a diffused layer/a poly silicon-polysilicon gate electrode 2 are sequentially connected, and the electrode 2 is connected through the reverse conductivity type diffused layer 7 to a semi conductor substrate. A diode 13 is formed between the diffused layer/the sub strate at a gate electrode 11, and the diode 13 depends on the substrate and the impurity density of the layer 7 with a reverse breakdown strength of approx. 17-25V. Accordingly, a gate voltage below reverse breakdown strength is applied to the electrode 11 to measure characteristics. Thus, even if a strong electric field is applied during diffusing step, the rise of the gate potential is limited by the reverse breakdown strength of the diode 13. Therefore, a writing does not occur.
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